1. Field of the Invention
This invention relates to an apparatus for storing and retrieving numerous microfiche cards and displaying microfilm images on the cards, and in one aspect, to an apparatus for protecting the microfiche card during its mechanical retrieval from the storage carousel and the return of the card to the carousel.
2. Description of the Art
Machines for storing microfiche and for the retrieval of the microfiche to display individual images and project the same either on a screen, make a hard copy of the image, or position the microfiche such that a video signal may be generated by scanning the film for projection on a remote terminal are known. Examples of patents disclosing a microfiche retrieval system of the type addressed herein are U.S. Pat. No. 3,429,436, issued Feb. 25, 1969 to E. H. Irasek; U.S. Pat. No. 4,190,899, issued Feb. 26, 1980 to D. H. Smith et al; and U.S. Pat. No. 4,273,427, issued June 16, 1981 to D. C. Bailey. Numerous additional patents exist relating to devices for scanning microfiche or other microfilm image-supporting media such that the information on the microfilm image may be retrieved and reread by a projection image or by duplication on a CRT terminal. Examples of such devices are illustrated in U.S. Pat. No. 3,753,240, issued Aug. 14, 1973 to Roy L. Merwin; and U.S. Pat. No. 3,604,850, issued Sept. 14, 1971 to R. R. Eckenbrecht et al.
These systems provide a means for storing information which must be stored on a photographic medium and retrievable automatically by suitable coding logic stored in a computer. The actual storage and retrieval device will respond to the signals to rotate the storage file to locate the predetermined microfiche card at the retrieval opening such that it may be removed from the file and a specific image on the card positioned for reading the image either by projection, by scanning, or by copying.
The present invention thus deals with the file for storing the microfiche cards, accessing the microfiche cards to a card-handling mechanism for picking the cards from the file and operable on an X-Y axis to orient a specific image on the card at the film reading station, for moving the card to position another image at the film reading station and then to the structure for reinserting the microfiche card in the file, delivering the card to the operator through an opening into the file, or dumping the card from the file. The mechanism utilized for storing the microfiche card comprises a pair of trays, fixed on a rotatable axis and positionable to place a given one of the storage slots in one or the other of the trays at the access opening. Picker fingers then grasp the microfiche card, lift the card slightly off the tray, straighten (by tensioning) the leading edge of the card and withdraw it from the file. Separators for separating the adjacent cards from the selected card aid the fingers to grasp the microfiche card and position the card at the viewing station. Thus, the visual patterns stored in the microfiche card can be optically scanned to convert the image pattern electrically to signals which by analog-to-digital conversion and speed conversion are transmitted to remote terminals along with alphanumeric data for review by an operator. The equipment of this invention will make visual patterns stored on-line in a control system totally computer driven and accessible. When the information has been viewed the microfiche card is reinserted into the slot in the tray and the separators for the adjacent microfiche cards are returned to their normal position and the tray carousel is rapidly indexed to locate the next microfiche card called for by the computer.
During insertion of the microfiche cards, which are four to eight mils in thickness and quite susceptible to bending or buckling during mechanical handling of the microfiche cards, the cards may become damaged or destroyed. It is therefore important the equipment handle the cards in such a manner as to sense if some abnormality exists in the card or in the operation of the equipment such that the card may be reinserted without being forced, if in fact, the card approaches the storage slot and strikes an obstruction causing it to be slightly bent, bowed, or buckled.
Thus, it is the purpose of the present invention to provide a guiding and a sensing device which will stop the operation of the machine when the presence of a buckle in the card or a bowed card is sensed upon its reinsertion into the storage tray. This device will permit the computer to move the card to a retracted position and attempt reinsertion to allow the card to follow its predetermined course and not apply force which would result in permanent damage to the microfiche card and all the information contained thereon.